Conventional such fire suppression systems incorporate a cylinder containing fire suppressant foam under pressure with an actuator head in physical contact with the cylinder and a pneumatic actuator to activate the actuator head when use of the pressurised foam for fire suppressant purposes is required. The system also utilizes a series of heat sensitive sensors in the region where fire suppression may be required, which region may be somewhat removed from the location of the cylinder and actuator. This conventional system has proven, in some circumstances, to be very dangerous. Physical interference with the actuator head has resulted in severe injuries to people engaged in that activity. In any event, a 3 to 5% failure rate of installed equipment has arisen, since fine adjustments necessary in the actuator head have proven too critical. Obviously such a system which fails to operate in a fire situation is highly undesirable. A further problem which has arisen with this conventional fire suppression system is that the pneumatic actuator may be activated by local heat, leading to the spraying of foam in a remote area where no fire is evident.